Use of wearable technology to enhance response to the Coronavirus (COVID-19) pandemic

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The authors propose a wearable bracelet to kerb the spread of Coronavirus (COVID-19).

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The first feature is an infrared thermometer for early screening on a population level.

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The second feature is a GPS for contact tracing of infection chains.

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The third feature of the bracelet is a RFID for tracking immunity status.

Diastolic dysfunction grading, echocardiographic and electrocardiogram findings in 50 patients with apical hypertrophic cardiomyopathy

INTRODUCTION

Apical Hypertrophic Cardiomyopathy (Apical HCM) is an uncommon variant of hypertrophic cardiomyopathy, but it is relatively more common in Asian countries. This is a retrospective, non-randomised, single centre study of patients with Apical HCM focusing on their diastolic dysfunction grading, echocardiographic parameters and electrocardiograms (ECG).

METHODS

All Apical HCM patients coming for clinic visits at the Institut Jantung Negara from September 2017 to September 2018 were included. We assessed their echocardiography images, grade their diastolic function and reviewed their ECG on presentation.

RESULTS

Fifty patient were included, 82% (n=41) were males and 18% (n=9) females. The diastolic function grading of 37 (74%) patients were able to be determined using the updated 2016 American Society of Echocardiography (ASE) diastolic guidelines. Fifty percent (n=25) had the typical ace-ofspades shape left ventricle (LV) appearance in diastole and 12% (n=6) had apical pouch. All patients had T inversion in the anterior leads of their ECG, and only 52% (n=26) fulfilled the ECG left ventricular hypertrophy (LVH) criteria. Majority of our patients presented with symptoms of chest pain (52%, n=26) and dyspnoea (42%, n=21).

CONCLUSION

The updated 2016 ASE guideline makes it easier to evaluate LV diastolic function in most patients with Apical HCM. It also helps in elucidating the aetiology of dyspnoea, based on left atrial pressure. Clinicians should have a high index of suspicion for Apical HCM when faced with deep T inversion on ECG, in addition to a thick LV apex with an aceof- spades appearance during diastole.

Echocardiographic and electrocardiographic presentations of patients with endomyocardial biopsy-proven cardiac amyloidosis

OBJECTIVE

Cardiac amyloidosis is under diagnosed and its prevalence is unknown. This is a retrospective, nonrandomised, single centre study of patients with endomyocardial biopsy-proven cardiac amyloidosis focusing on their echocardiographic and electrocardiogram (ECG) presentations. This is the first case series in Malaysia on this subject.

METHODS

We identified all of our endomyocardial biopsyproven cardiac amyloidosis patients from January 2010 to January 2018 and reviewed their medical records. All patients echocardiographic and ECG findings reviewed and analysed comparing to basic mean population value.

RESULTS

In total there are 13 biopsy-proven cardiac amyloidosis patients. All of the biopsies shows light chain (AL) amyloid. Majority of the patients (8, 61.5%) is male, and most of our patients (8, 61.5%) is Chinese. All seven patients on whom we performed deformation imaging have apical sparing pattern on longitudinal strain echocardiogram. Mean ejection fraction is 49.3%, (SD=7.9). All patients have concentric left ventricular hypertrophy and right ventricular hypertrophy. Diastolic dysfunction was present in all of our patients with nine out of 13 patients (69.2%) having restrictive filling patterns (E/A ≥2.0 E/e' ≥15). On electrocardiogram, 12 (92%) patients have prolonged PR interval (median 200ms, IQR 76.50ms) and 9 (69.2%) patients have pseudoinfarct pattern.

CONCLUSION

Echocardiography plays an important role in diagnosing cardiac amyloidosis. The findings of concentric left ventricular hypertrophy with preserved ejection fraction without increased in loading condition should alert the clinician towards its possibility. This is further supported by right ventricular hypertrophy and particularly longitudinal strain imaging showing apical sparing pattern.

Initiation of insulin for type 2 diabetes mellitus patients: what are the issues? A qualitative study

INTRODUCTION

Type 2 diabetes mellitus is a progressive condition in which the pancreatic beta-cell function deteriorates with increasing duration of the disease. When good glycaemic control is not achieved despite adherence to oral hypoglycaemic drugs, healthy diet and lifestyle, insulin should be initiated. However, this is often delayed due to various reasons. We aimed to determine the issues relating to insulin initiation for diabetic patients managed in primary care polyclinics in Singapore.

METHODS

Qualitative data was obtained during four focus group discussions, with participation from healthcare professionals (HCPs), including physicians and nurses, and type 2 diabetes mellitus patients. The data was transcribed into text, coded and grouped into themes.

RESULTS

Launching the topic and doctor-patient communication on insulin therapy were key issues in insulin initiation. Patient barriers to insulin commencement included: refusal to acknowledge the need for insulin therapy; its perception as a social stigma, an inconvenient mode of treatment or punishment for failure; and fear of needles, side-effects and complications. The HCP's attitude and experience with insulin therapy were also possible barriers.

CONCLUSION

Our findings highlight that insulin initiation is affected by the complex interaction between the patients and HCPs, and other system factors. Patients may harbour misconceptions about insulin due to the late introduction of insulin therapy by HCPs or the way the therapy is being communicated to them. The key issues to address are the disparity in perceptions of diabetic control between HCPs and patients, and education regarding the need for insulin therapy.

Osteosarcoma in pediatric and young adult patients: The Singapore experience

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Background: There is limited information on treatment and survival regarding these tumors in the South East Asia region. We thus attempted to investigate the incidence, the treatment modalities used and the outcome of OS patients treated at the two major pediatric oncology hospitals in Singapore. Methods: A comprehensive list of patients with OS treated at the Department of Pediatrics National University Hospital and KK Women's and Children's Hospital, Singapore between April 1980 and May 2006 was generated. During the study interval, patients received neoadjuvant chemotherapy followed by definitive surgery consisting of either limb-salvage or amputation followed by adjuvant chemotherapy. Chemotherapy included combination of cisplatin and doxorubicin as per the European Osteosarcoma InterGroup (EOI) and as per the Memorial Sloan-Kettering Cancer Center's (MSKCC) T12 protocols. Treatment of subsequent relapses consisted of various combinations of methotrexate, ifosfamide, etoposide, other, and/or surgery. Results: Of the total 49 patients with OS, 14 (29%) patients presented with metastatic OS (lungs, n=13; skip lesion, n=1). The median age of diagnosis of OS was 12.4 (range, 6.6 - 17.9 years). Mean survival after diagnosis of OS was 13.4 years (95% CI, 9.1 - 17.8 years). The two and five-year overall survival were 56.4 % ± 86.9 % (se) and 37.5 % ± 73.9 % (se) respectively for the entire cohort. The two and five-year overall survival were 77.9 % ± 100 % (se) for patients who were treated as per the MSKCC T12 protocols. The two and five-year overall survival were 51.8 % ± 86.2 % (se) and 33.8 % ± 72.6 % respectively for patients who were treated as per the EOI regimen. Conclusions: Survival from OS in Singapore appears to be improving since the multi-drug combination chemotherapy was introduced in 2002. The rarity and complexity of OS makes it crucial for patients diagnosed with this tumor to seek a centralized multi-disciplinary Musculoskeletal Oncology team.

No significant financial relationships to disclose.

Mycobacterium fortuitum catheter-related sepsis in acute leukaemia

We report Mycobacterium fortuitum (M. fortuitum) catheter-related sepsis in a five-year-old boy with acute lymphoblastic leukaemia (ALL). This is the first reported case of M. fortuitum infection seen in our paediatric oncology patients. The patient was in haematological remission and receiving maintenance chemotherapy via an indwelling central venous catheter (Port-a-Cath). He was febrile, toxic-looking and was in respiratory distress. Clinically, he had a right pleural effusion and gross hepatomegaly. The patient was lymphopaenic and had deranged liver function test. Repeat paired blood cultures were positive for M. fortuitum. The catheter was promptly removed and he was treated aggressively with intravenous amikacin, cefoxitin, ciprofloxacin, trimethoprim-sulfamethoxazole and oral clarithromycin, with good clinical response. The patient remained well without further complications while on chemotherapy. M. fortuitum is an uncommon cause of catheter-related infection in patients with malignancies. Removal of an infected catheter is necessary for complete control of atypical mycobacterial infection in an immunosuppressed patient.

Closed versus partially ventilated endotracheal suction in extremely preterm neonates: physiologic consequences

This randomized cross over study aimed to compare the severity and incidences of desaturation and bradycardia between the partially ventilated endotracheal suction method (PVETS) and closed tracheal suction system (CTSS) in extremely preterm neonates. Fifteen intubated and ventilated extremely low birth weight preterm infants (mean birth weight 689g) randomly underwent both suction techniques within a 12-h period to obtain a paired reading group. The process was repeated 24-48h apart until three pairs of reading groups were collected. Changes in oxygen saturation measured with pulse oximetry and heart rate changes measured with electrocardiogram were recorded using Hewlett-Packard m240A monitor trending software. The mean of each parameter's variation from baseline was obtained using SPSS descriptive statistics and analyzed using SPSS repeated measures ANOVA. Fisher Exact Test was used to analyze the incidence of desaturation and bradycardia. The closed tracheal suction system reported a significantly smaller degree of oxygen saturation fall (P<0.005) and significantly fewer incidences of desaturation. There was also a significantly smaller degree of heart rate reduction although episodes of bradycardia were not significantly different between the two methods. Oxygen saturation and heart rate were significantly more stable during the use of CTSS compared to PVETS in the extremely low birth weight preterm population.

Functional coupling, desensitization and internalization of virally expressed mu opioid receptors in cultured dorsal root ganglion neurons from mu opioid receptor knockout mice

Although mu opioid receptors desensitize in various cell lines in vitro, the relationship of this change in signaling efficacy to the development of tolerance in vivo remains uncertain. It is clear that a system is needed in which functional mu opioid receptor expression is obtained in appropriate neurons so that desensitization can be measured, manipulated, and mutated receptors expressed in this environment. We have developed a recombinant system in which expression of a flag-tagged mu opioid receptor is returned to dorsal root ganglia neurons from mu opioid receptor knockout mice in vitro. Flow cytometry analysis showed that adenoviral-mediated expression of the amino-terminal flag-tagged mu opioid receptor in neurons resulted in approximately 1.3x10(6) receptors/cell. Many mu opioid receptor cell lines express a similar density of receptors but this is approximately 7x greater than the number of endogenous receptors expressed by matched wild-type neurons. Inhibition of the high voltage-activated calcium currents in dorsal root ganglia neurons by the mu agonist, D-Ala(2), N-MePhe(4), Gly(5)-ol-enkephalin (DAMGO), was not different between the endogenous and flag-tagged receptor at several concentrations of DAMGO used. Both receptors desensitized equally over the first 6 h of DAMGO pre-incubation, but after 24 h the response of the endogenous receptor to DAMGO had desensitized further than the flag- tagged receptor (71+/-3 vs 29+/-7% respectively; P<0.002), indicating less desensitization in neurons expressing a higher density of receptor. Using flow cytometry to quantify the percentage of receptors remaining on the neuronal cell surface, the flag-tagged receptor internalized by 17+/-1% after 20 min and 55+/-2% after 24 h of DAMGO. These data indicate that this return of function model in neurons recapitulates many of the characteristics of endogenous mu opioid receptor function previously identified in non-neuronal cell lines.

When is a mediastinal mass critical in a child? An analysis of 29 patients

The aims of this study were to determine the pattern of presentation of childhood mediastinal masses in our community and to identify factors associated with the development of acute airway compromise. The authors retrospectively reviewed the records of 29 consecutive patients with mediastinal masses managed at their institution between January 1995 and December 2001. Demographic data, mass characteristics, clinical presentation, and surgical procedures were recorded. Seven patients (24.1%) were asymptomatic at presentation. Eight (27.6%) were classified as having acute airway compromise at presentation. Respiratory symptoms and signs were the most common mode of presentation (58.6% and 55.2%, respectively). The most common histological diagnosis was neurogenic mass (37.9%), followed by lymphoma (24.1%). Most masses were located in the superior mediastinum (41.1%). Factors associated with the development of acute airway compromise were (1) anterior location of the mediastinal mass (P=0.019), (2) histological diagnosis of lymphoma (P=0.008), (3) symptoms and signs of superior vena cava syndrome (P=0.015 and 0.003, respectively), (4) radiological evidence of vessel compression or displacement (P=0.015), (5) pericardial effusion (P=0.015), and (6) pleural effusion (P=0.033). Clinical presentation of childhood mediastinal masses is often nonspecific or incidental. Yet they have the propensity of developing acute airway compromise, which is closely associated with superior vena cava obstruction. Such patients should be managed as a complex cardiorespiratory syndrome, termed "critical mediastinal mass syndrome", by an experienced multidisciplinary team.

Nociceptin/orphanin FQ modulation of rat midbrain dopamine neurons in primary culture

Previous microdialysis studies have identified a suppressive effect of the novel opioid peptide nociceptin (also known as orphanin FQ) on dopamine release from mesolimbic neurons. In order to further evaluate the locus of this action, we investigated nociceptin's action in an in vitro model system, namely midbrain dopamine neurons in primary culture. Immunohistochemical analysis revealed abundant tyrosine hydroxylase- and GABA-immunoreactive neurons, with a strong correlation between tyrosine hydroxylase content and basal endogenous dopamine release. Nociceptin (0.01-100 nM) suppressed basal dopamine release by up to 84% (EC50=0.65 nM). This action was reversible by drug removal and attenuated by co-application of the non-peptidergic ORL1 antagonist, Compound B. Nociceptin had no significant effect on dopamine release evoked by direct depolarization of the terminals with elevated extracellular K+, suggesting that nociceptin suppresses dopamine release by modulating the firing rate of the dopamine neurons. Nociceptin also suppressed GABA release from the cultures (45% maximal inhibition; EC50=1.63 nM). Application of the GABA-A antagonist, bicuculline, elevated extracellular dopamine concentrations but the dopamine release inhibiting property of nociceptin persisted in the presence of bicuculline. The NMDA receptor antagonist, D(-)-2-amino-5-phosphononpentanoic acid (AP-5) had no effect on basal dopamine release and failed to modify nociceptin's inhibitory effects. Thus, nociceptin potently modulates dopamine release from midbrain neurons most likely as a result of a direct suppression of dopamine neuronal activity.

Clinics in diagnostic imaging (90). Childhood nasopharyngeal carcinoma

An 11-year-old boy presented with a nasopharyngeal mass that was thought to represent a juvenile angiofibroma based on the initial clinical and radiological evaluation. Partial tumour resection was performed. Resected specimen revealed histological diagnosis of undifferentiated carcinoma. Further evaluation of the tumour including MR imaging, radioisotope bone scan, CT thorax and abdomen were performed. Differential diagnoses of childhood nasopharyngeal masses were discussed. The differences between childhood NPC and adult NPC, rhabdomyosarcoma, malignant lymphoma and juvenile nasopharyngeal angiofibroma were also discussed.

Intracranial germ cell tumour: experience of a Singaporean institution over 11-year period

BACKGROUND

Intracranial germ cell tumours (IGCT) are rare. We present our experience in Therapeutic Radiology Department, National Cancer Centre, Singapore.

METHODS

A retrospective study was conducted through case notes review on 25 patients with IGCT referred between January 1988 and January 1999.

RESULTS

The median age at diagnosis was 13 years (range 6-22). The tumours were mainly pineal germinoma (72%). Median follow-up for living patients was 2.57 years (range 0.12-10.8). Median radiotherapy (RT) dose to whole brain, primary site and spine was 35.3,54 and 30 Gys respectively. Four to six cycles of BEP or JEB chemotherapy (CM) were given in 10 patients. As for the whole study group, the seven-year overall survival (OS) and recurrence-free survival (RFS) were 86% (95% CI 72-100) and 78% (95% CI 60-100) respectively. The 10-year OS and RFS were 65% (95% CI 36-100) and 78% (95% CI 60-100) respectively. The germinoma group had 75% 10-year OS and 86% 10-year RFS. Mixed germinoma and non-germinoma germ cell tumours (NGGCT) group had 50% one-year RFS and 44% two-year OS. Acute side-effects of RT and CM were minimal. There was no statistically significant difference in side-effects when treatment modalities were compared.

CONCLUSION

In the treatment of intracranial germinoma, we recommend biopsy and CSRT. Primary chemotherapy (+/- low-dose cranial RT) should be used in the protocol or clinical trial settings. Chemo-radiotherapy is recommended for mixed germinoma and NGGCT. A multicentre trial is needed to address various controversial issues.

Paediatric extracranial germ cell tumours: a retrospective review

INTRODUCTION

Germ cell tumours (GCTs) are rare, constituting 3% of all childhood malignancies. The aim of this study was to analyse the epidemiology and outcome of these patients.

MATERIALS AND METHODS

A retrospective, cohort study was conducted on 38 paediatric patients presenting with extracranial GCTs, treated at the Singapore General Hospital, Tan Tock Seng Hospital and Kandang Kerbau Women's and Children's Hospital from 1 January 1989 to 30 June 1999. The median age at diagnosis was 1.7 years (0 to 13 years).

RESULTS

There was no sex or racial preponderance. Eighteen patients (47.3%) had teratomas, 16 (42.1%) had yolk sac tumours, 1 (2.6%) had dysgerminoma and 3 (7.9%) had mixed GCTs. Thirty-four patients (89.5%) had Stage I disease, 1 (2.6%) had Stage II disease, 1 (2.6%) had Stage III disease and 2 (5.3%) had metastatic disease. Complete tumour resection was achieved in 36 of the 38 patients (95%). Cisplatin-based combination chemotherapy was given to 11 patients (28.9%). None of the patients received radiotherapy. Complications from chemotherapy included anaemia requiring packed red cell transfusion (n = 3), Port-a-cath sepsis requiring removal (n = 1), febrile neutropenia (n = 1) and nephropathy (n = 1).

CONCLUSION

Using the Kaplan-Meier life tables, the overall and event-free survivals at 10 years for the patients with malignant GCTs were 96% and 88%, respectively, with a mean follow-up period of 5.1 years (0.7 to 10 years). The majority of the patients presented with early Stage I disease and this contributed to our high survival rate.

Congenital acute megakaryoblastic leukemia (M7) with chromosomal t(1;22)(p13;q13) translocation in a set of identical twins

Chromosomal translocations at t(1;22)(p13;q13) have been reported to occur in a number of infants with acute megakaryoblastic leukemia. A set of female twins with acute megakaryoblastic leukemia are reported with this unique translocation of 1p13 to 22q13. The twins presented at 2 months of age with fever and poor feeding and subsequently developed progressive hepatosplenomegaly. One twin died before treatment could be started; the other became septicemic 5 days after initiation of chemotherapy and eventually died.

Clinics in diagnostic imaging (37). Germinoma of the pineal gland

Tumours occurring in the region of the pineal gland are uncommon in paediatric patients but may manifest with typical signs and symptoms. A 6-year-old boy with precocious puberty caused by a germinoma of the pineal gland detected on skull radiographs and confirmed on MR imaging is reported. The different types of tumours occurring in the region of the pineal gland and their imaging findings are discussed.

Thrombocytosis in childhood

INTRODUCTION

Thrombocytosis is a common condition in infancy and childhood. There are very few paediatric literature on its incidence and clinical significance.

METHOD

We conducted a prospective study over 18 months (January 1993 to June 1994) on all patients admitted with a platelet count done. Cases with platelet count > 600 x 10(9)/L were reviewed and followed-up. Serial platelet count were done at 1 week, 2 weeks, 3 weeks, 4 weeks, and then monthly until it normalised.

RESULTS

One hundred and thirty-five cases out of 10,288 admissions had raised platelet count. There was a preponderance of male (sex ratio M:F = 1.7:1). Majority was less than 1 year old. Seventy-eight percent had associated infection of which 2/3 were due to bacterial infections, Pneumonia was the most common bacterial infection associated with thrombocytosis whilst gastroenteritis was the most common cause for non-bacterial infection and Kawasaki's disease constituted the majority of the non-infective etiology. Cases with platelet count > 900 x 10(9)/L, 73.3% were due to bacterial infection. Three cases of Kawasaki's disease had platelet counts > 900 x 10(9)/L. Fifty-two percent of cases developed thrombocytosis within 4 days of illness. In nonbacterial infection, the thrombocytosis normalised by about 1 week after onset. For bacterial infection, the thrombocytosis normalised later depending on the severity of infection. In majority of the Kawasaki's disease, the platelet count normalised by the third week.

CONCLUSION

Primary thrombocytosis is rare in paediatric age group. None of the cases developed any symptoms associated with thrombocytosis. Secondary thrombocytosis is a benign and common phenomenon in children.

Infections in acute lymphoblastic leukaemia

We did a retrospective study of all acute lymphoblastic leukaemia (ALL) patients on United Kingdom ALL protocol who were admitted for febrile neutropenia. The aim of the study was to document the types of infections and aetiological agents associated with febrile neutropenia and to document the factors affecting mortality. Over the 8 1/2-year period from 1986 to June 1995, there were 77 episodes in 32 children with a mean of 2.4 episodes. Morbidity due to infection was 61%; unknown causes of fever contributed 39%. Of the microbiologically documented infections, majority were Gram-negative bacteraemia. There were 7 deaths (22%) during the study period, 3 (9%) of which were due to overwhelming sepsis, with 4 contributed by the relapse status of the leukaemia. Mortality was increased by prolonged neutropenia, relapse of the leukaemia and invasive fungal infection.

Use of a mixture of medium-chain triglycerides and longchain triglycerides versus long-chain triglycerides in critically ill surgical patients: a randomized prospective double-blind study

Twenty critically-ill surgical patients who needed total parenteral nutrition were randomly enrolled in a double-blind study comparing two intravenous fat emulsions: one containing a mixture of 50% medium-chain triglycerides and 50% long-chain triglycerides and another containing 100% longchain triglycerides. The purpose of this study was to investigate metabolic and biochemical differences between both emulsions with special reference to liver enzymes. After a baseline period of 24 h with only glucose and NaCl infusion, the lipid emulsion was added continuously during 24 h over 5 days. The parenteral nutrition was administered in mixture bags containing amino-acids, glucose and lipids together. Two-thirds of the non-protein calories were administered as glucose 40% and one third as either long-chain triglycerides or a mixture of medium-chain triglycerides and long-chain triglycerides. The total amount of non-protein calories received was the measured energy expenditure during the baseline period plus 10% and was fixed during the study. Plasma substrate concentrations, energy expenditure, and nitrogen balance were determined and arterial blood samples were taken. No toxic effects or complications attributable to one of the two emulsions were observed. There was no significant difference in energy expenditure, nitrogen balance, liver function tests, carnitine, transferrin, pre-albumin, albumin, cholesterol, triglycerides and free fatty acids. The only parameter that showed a different pattern of reaction between the two emulsions was serum bilirubin concentration. In this study no evidence of any advantageous effect of a mixture of medium-chain triglycerides and long-chain triglycerides was seen.

Effects of 5-oxo-6,8,11,14-eicosatetraenoic acid on expression of CD11b, actin polymerization, and adherence in human neutrophils

Human neutrophils contain a highly specific dehydrogenase that converts 5-hydroxy-6,8,11,14-eicosatetraenoic acid to 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). 5-Oxo-ETE is a potent stimulator of calcium mobilization, chemotaxis, and aggregation in these cells and has similar effects on eosinophils. The primary objectives of the current study were to determine whether this compound could increase the surface expression of integrins and stimulate actin polymerization in neutrophils. 5-Oxo-ETE stimulated the expression of CD11b and, to a lesser extent, CD11c, on neutrophils, but had no significant effects on the expression of CD11a, CD16 (Fc gammaRIII), or CD32 (Fc gammaRII). Surface expression of CD11b in response to 5-oxo-ETE was maximal after 12 min and remained constant thereafter. The EC50 for this response (50 nM) was lowered to 20 nM by preincubation of neutrophils with PMA. 5-Oxo-ETE (EC50, 10 nM) also rapidly stimulated actin polymerization in neutrophils, with a maximal response at 20 s. This response was blocked by pretreatment of neutrophils with the Gi protein inhibitor, pertussis toxin, and by homologous desensitization due to preincubation with 5-oxo-ETE. However, preincubation with leukotriene B4 or platelet-activating factor had no effect on the response of neutrophils to subsequent addition of 5-oxo-ETE. The adherence of neutrophils to plasma-coated plastic was also stimulated by 5-oxo-ETE with a time course similar to that for the surface expression of CD11b. Low concentrations of PMA (0.3 nM) enhanced this response. These results raise the possibility that 5-oxo-ETE could contribute to the infiltration of neutrophils into inflammatory sites.

Effects of 5-oxo-6,8,11,14-eicosatetraenoic acid on expression of CD11b, actin polymerization, and adherence in human neutrophils

Human neutrophils contain a highly specific dehydrogenase that converts 5-hydroxy-6,8,11,14-eicosatetraenoic acid to 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). 5-Oxo-ETE is a potent stimulator of calcium mobilization, chemotaxis, and aggregation in these cells and has similar effects on eosinophils. The primary objectives of the current study were to determine whether this compound could increase the surface expression of integrins and stimulate actin polymerization in neutrophils. 5-Oxo-ETE stimulated the expression of CD11b and, to a lesser extent, CD11c, on neutrophils, but had no significant effects on the expression of CD11a, CD16 (Fc gammaRIII), or CD32 (Fc gammaRII). Surface expression of CD11b in response to 5-oxo-ETE was maximal after 12 min and remained constant thereafter. The EC50 for this response (50 nM) was lowered to 20 nM by preincubation of neutrophils with PMA. 5-Oxo-ETE (EC50, 10 nM) also rapidly stimulated actin polymerization in neutrophils, with a maximal response at 20 s. This response was blocked by pretreatment of neutrophils with the Gi protein inhibitor, pertussis toxin, and by homologous desensitization due to preincubation with 5-oxo-ETE. However, preincubation with leukotriene B4 or platelet-activating factor had no effect on the response of neutrophils to subsequent addition of 5-oxo-ETE. The adherence of neutrophils to plasma-coated plastic was also stimulated by 5-oxo-ETE with a time course similar to that for the surface expression of CD11b. Low concentrations of PMA (0.3 nM) enhanced this response. These results raise the possibility that 5-oxo-ETE could contribute to the infiltration of neutrophils into inflammatory sites.

Experience of varicella vaccination in acute lymphoplastic leukaemia

Varicella is a common benign childhood illness. Rarely, serious complications arise. Immunocompromised patients usually suffer a more serious form of the illness. It is therefore prudent to prevent the infection in this group of patients. Varicella vaccination has been proven by several workers to be effective in both healthy children and adults as well as in leukaemic children. As the vaccine had not been licensed for sale in Singapore, we could only import 10 doses of the vaccine under special license. This was given to 8 leukaemic children. Of this, 5 seroconverted after the first dose. Two patients had the benefit of a repeat vaccination 3 months later. Both subsequently seroconverted. Two of the patients died from a relapse of the illness, a year and 2 years after the vaccination. None of the patients developed any side effects of fever and pain or varicella or zoster after the immunisation even though there was close contact with chicken pox. Although the study sample was small, it appeared that the vaccine was safe and efficacious in leukaemic children, especially after a 2-dose injection.

Expression of the lacZ reporter gene in the rat basal forebrain, hippocampus, and nigrostriatal pathway using a nonreplicating herpes simplex vector

We recently demonstrated the efficacy of a nonreplicating herpes simplex type 1 virus construct, employing the Moloney murine leukemia virus long terminal repeat promoter, in providing long-term expression of the lacZ gene in rat hippocampal neurons. We now report the utility of this construct in expressing the reporter gene in neurons of the basal forebrain and substantia nigra and examine the spread of the virus to other brain regions. Dorsal and ventrolateral hippocampal formation injection of the virus resulted in numerous beta-gal-expressing cells in the stratum pyramidale, stratum oriens, stratum lacunosum-moleculare, and stratum granulosum. Scattered cells of the medial septum/diagonal band were positively stained following direct injection into this region. More intense staining of the basal forebrain was observed following hippocampal injection as a result of retrograde transport of the virus as shown by PCR analysis of viral DNA. Hippocampal injection also resulted in positive cell staining in several other afferent projection nuclei, namely, the supramammillary bodies, dorsal and caudal linear raphe, and perirhinal/entorhinal cortex. Very few cells were labeled around injection sites in the striatum or substantia nigra. However, substantia nigra zona compacta cells were blue following striatal injection, as were pallidal neurons following nigral injection. These data demonstrate the feasibility of using this virus construct to express foreign genes such as neurotrophic factors in basal forebrain and substantia nigra neurons, taking advantage of retrograde transport of the virus to preserve local anatomy.

Lack of Fos-like immunoreactivity after spontaneous seizures or reinduction of status epilepticus by pilocarpine in rats

Acute seizures and status epilepticus induced by pilocarpine lead to the expression of Fos-like immunoreactivity in several specific brain areas in a manner similar to that of other models of limbic seizures. Upon development of status epilepticus after systemic pilocarpine injection, animals develop a state where chronic spontaneous seizures recur. Assessment of Fos-like immunoreactivity after such spontaneous seizures or after status epilepticus reinduction reveals either lack of staining or a weak reaction in a few brain areas including the ventral tip of the dentate gyrus, prepiriform, lateral piriform and perirhinal cortices, and scattered locations throughout temporal neocortex. Our results suggest that status epilepticus induction may lead to a long-lasting state of Fos down-regulation.

Microcalorimetric study of mitochondria isolated from fish liver tissue

We determined the thermogenesis curves of mitochondria isolated from fish liver tissue by using an LKB 2277 Bioactivity Monitor. After isolation from the fish liver, mitochondria still have activity and can live for a long time by using the stored nutrients. We calculated the recovery rate constants of mitochondria. We found that the thermogenesis curves of mitochondria are similar to those obtained from prokaryotic cells, but not similar to those obtained from eukaryotic cells. We determined the metabolic thermogenesis curves of mitochondria isolated from two kinds of carp liver tissue, scattered-scaled mirror carp and harvest carp. There are some important similarities and some important differences between these thermogenesis curves.

MtDNA phylogeography of the California newt, Taricha torosa (Caudata, Salamandridae)

Thirty-six individuals of the California newt, Taricha torosa, representing 22 populations from throughout the range of the two currently recognized subspecies, torosa and sierrae, were examined for sequence variation in a segment (375 bp) of the mitochondrial (mt) cytochrome b gene. The maximum sequence divergence within T. torosa is about 9%. Phylogenetic analyses used the sister taxa T. rivularis and T. granulosa as outgroups. Eighteen haploid sequence types found in T. torosa were grouped by parsimony, maximum likelihood, and neighbor-joining analyses into five mitochondrial clusters: two in torosa (the northern and southern clusters) and three in sierrae (the northern, central, and southern clusters). The southern sierrae cluster apparently shared a most recent common ancestor with the northern torosa cluster. The approximate time of sequence divergence within the current species was calibrated using the known fossil record (0.8% divergence per million years or 0.01 maximum likelihood distance per million years). Phylogenetic implications of mtDNA sequence variation for evolution and biogeography of the T. torosa species complex are discussed.

Unusual manifestations of Mycoplasma pneumoniae infection in children

Mycoplasma pneumoniae infection is no longer a benign condition it was originally thought to be. Many extrapulmonary manifestations affecting major organ systems like the central nervous system, cardiovascular system, haematological system, gastrointestinal system, musculoskeletal system and renal system have been described. Early recognition of these manifestations is often difficult and serological diagnosis may not be helpful. Three patients with large pleural effusions, encephalitis, hemiplegia, hepatitis, autoimmune haemolytic anaemia and renal failure are discussed to highlight the many varied presentations associated with this infection.

Activation of the neutrophil bactericidal activity for nontypable Haemophilus influenzae by tumor necrosis factor and lymphotoxin

Previous studies have suggested that, in vivo, activated T lymphocytes and neutrophils are important in immunity to nontypable Haemophilus influenzae. We now extend this work by showing that neutrophils pretreated with products of activated T lymphocytes or activated macrophages show significantly enhanced killing of nontypable H. influenzae. Lymphotoxin, a product of activated T lymphocytes, significantly enhanced the neutrophil-mediated killing of nontypable H. influenzae, and tumor necrosis factor, produced by activated T lymphocytes as well as macrophages stimulated by activated T lymphocytes, also significantly increased the bactericidal activity of neutrophils. These cytokine-induced effects were seen with short pretreatment times of neutrophils and were maximal by 30 min. The killing of H. influenzae by neutrophils required the presence of heat-labile opsonins. In the absence of these opsonins, both tumor necrosis factor and lymphotoxin were unable to promote the killing of the bacteria by neutrophils. Furthermore, the results showed that tumor necrosis factor-primed neutrophils displayed significantly increased expression of CR3 and CR4 that was associated with increased phagocytosis of complement-opsonized nontypable H. influenzae. These cytokines may play an important role in immunity toward nontypable H. influenzae by stimulating neutrophil bactericidal activity.

Neurophysiology and neuropharmacology of projections from entorhinal cortex to striatum in the rat

We studied projections from the entorhinal cortex (Ent) to the striatum in anesthetized rats using extra- and intracellular recording and multibarrel iontophoresis. The majority of recording were from the caudate-putamen (CPu) and core of the nucleus accumbens (AcbC). Electrical stimulation of the Ent evoked synaptic responses in 77% of tests with AcbC neurons and 48% of tests with CPu neurons. In the case of AcbC neurons, 61% of these tests proved to be excitatory and were often followed by inhibitory phases. In contrast to this, only 18% of tests from CPu neurons were excitatory. Intracellular HRP labeling showed that responsive cells were medium spiny neurons. During iontophoretic experiments, application of the glutamatergic AMPA antagonist DNQX could selectively decrease or block excitatory responses. The GABAA antagonist bicuculline methiodide increased cellular firing rates and could reveal excitatory responses, suggesting block of a short-latency, short-duration inhibitory component. Ejection of the GABAB antagonist CGP-35348 could attenuate a later, longer-duration component of inhibition. The results indicate that the Ent excites striatal neurons at least in part by glutamatergic receptors and suggest that this excitation is followed by secondary prolonged GABAergic inhibition.

Chromosomal variation in the northwestern American newts of the genus Taricha (Caudata: Salamandridae)

Chromosomal variation was analysed in 22 populations of newts of the salmandrid genus Taricha of western North America, and compared with that of the eastern North American newts of the genus Notophthalmus. The karyotypes of the species Taricha and Notophthalmus were very similar. However, there was considerable variation in the distribution patterns of heterochromatins (revealed by C-banding) and in the sites of the nucleolar organizing region (NOR) (revealed by fluorochrome chromomycin A3 banding) within and between species of these two genera. Chromosomal variation patterns were interpreted in relation to a phylogenetic hypothesis derived from data on mitochondrial DNA sequences and allozyme variation. This study suggests that the pattern distributions of heterochromatins in chromosomes of Taricha are more derived than those of its sister taxon Notophthalmus. Furthermore, the chromosomal NOR types found in the southernmost and northernmost populations of T. granulosa, in the northernmost populations of T. t. sierrae, and in the southern populations of T. t. torosa are recently derived. The implications of this chromosomal variation for phylogeny and biogeography are discussed.

DNA stabilization and amplification from museum collections of extracts originally intended for allozyme analysis

Protein extracts originally prepared for isozyme electrophoresis two decades ago contain surviving DNA sequences susceptible to amplification by the polymerase chain reaction (PCR). Amplification was also possible after stabilization of such extracts on filter paper and immersion under mineral oil without refrigeration.

Interictal spiking increases 2-deoxy[14C]glucose uptake and c-fos-like reactivity

Although interictal spikes are thought to share pathophysiological mechanisms with partial-onset seizure discharges, positron emission tomographic studies of the interictal state have paradoxically shown focal hypometabolism whereas seizures produce hypermetabolism. To address this question, we performed functional mapping studies in an interictal spiking model in the rat. Recording screw electrodes were inserted through the skull bone so as to depress underlying cortex. Interictal spiking was subsequently induced by systemic administration of bicuculline methiodide. 2-deoxy[14C]glucose studies revealed increased glucose utilization in superficial and middle cortical layers at spiking screw sites. Nonspiking screw sites in the same animals and in controls did not show increased uptake. Convulsive seizures caused additional 2-deoxy[14C]glucose uptake at screw sites and in widespread forebrain areas. c-fos immunoreactivity occurred in superficial cortex at interictal spiking, but not nonspiking, sites. Convulsive seizures induced widespread forebrain c-fos immunoreactivity. These data suggest interictal epileptiform activity occurs in cells adjacent to cortical injury; these activate deeper layers via local connections. Interictal and ictal epileptiform states share common mechanisms, as both induce glucose hypermetabolism and immediate-early gene product activation. Possible reasons for failure to detect hypermetabolism in interictal human subjects are discussed.

Glutamatergic hippocampal formation projections to prefrontal cortex in the rat are regulated by GABAergic inhibition and show convergence with glutamatergic projections from the limbic thalamus

Anatomic and physiologic studies in the rat have shown projections from the hippocampal formation (HF) and mediodorsal (MD) thalamic nucleus to the medial prefrontal cortex (mPFC). The authors used multi-barrel iontophoresis to: confirm the neurotransmitter used in the projection from HF to mPFC; investigate the role of GABAergic inhibition in the regulation of this projection; and examine the functional convergence of projections from HF and MD onto single mPFC neurons. During HF stimulation, nine cells (6%) showed excitation followed by prolonged inhibition, 39 cells (26%) showed prolonged inhibition alone and 100 cells (68%) showed no clear response. In a further 12 cells that showed no predrug excitation to HF stimulation (representing 16% of the cells in this category), iontophoresis of the GABAA antagonist bicuculline methiodide (BMI) revealed excitatory responses. A total of six mPFC cells (38% of the cells showing excitatory responses to HF stimulation) showed convergent excitation to HF and MD thalamic (or adjacent paratenial nucleus) stimulation. Five out of eight (63%) of the predrug or BMI-revealed excitatory responses of mPFC neurons to HF stimulation were selectively decreased after AMPA antagonist iontophoresis (either CNQX or DNQX). These data confirm that the HF projection to prefrontal cortex is, at least in part, glutamatergic; suggest that the responses of mPFC neurons to activity in this HF pathway are regulated by GABAergic inhibition; and indicate that projections from HF and MD converge onto single mPFC neurons.

Circuit mechanisms of seizures in the pilocarpine model of chronic epilepsy: cell loss and mossy fiber sprouting

We used the pilocarpine model of chronic spontaneous recurrent seizures to evaluate the time course of supragranular dentate sprouting and to assess the relation between several changes that occur in epileptic tissue with different behavioral manifestations of this experimental model of temporal lobe epilepsy. Pilocarpine-induced status epilepticus (SE) invariably led to cell loss in the hilus of the dentate gyrus (DG) and to spontaneous recurrent seizures. Cell loss was often also noted in the DG and in hippocampal subfields CA1 and CA3. The seizures began to appear at a mean of 15 days after SE induction (silent period), recurred at variable frequencies for each animal, and lasted for as long as the animals were allowed to survive (325 days). The granule cell layer of the DG was dispersed in epileptic animals, and neo-Timm stains showed supra- and intragranular mossy fiber sprouting. Supragranular mossy fiber sprouting and dentate granule cell dispersion began to appear early after SE (as early as 4 and 9 days, respectively) and reached a plateau by 100 days. Animals with a greater degree of cell loss in hippocampal field CA3 showed later onset of chronic epilepsy (r = 0.83, p < 0.0005), suggesting that CA3 represents one of the routes for seizure spread. These results demonstrate that the pilocarpine model of chronic seizures replicates several of the features of human temporal lobe epilepsy (hippocampal cell loss, supra- and intragranular mossy fiber sprouting, dentate granule cell dispersion, spontaneous recurrent seizures) and that it may be a useful model for studying this human condition. The results also suggest that even though a certain amount of cell loss in specific areas may be essential for chronic seizures to occur, excessive cell loss may hinder epileptogenesis.

Glutamatergic excitatory responses of anterior cingulate neurons to stimulation of the mediodorsal thalamus and their regulation by GABA: an in vivo iontophoretic study

Anatomical and physiological studies in the rat have shown projections from the medial dorsal thalamus to the anterior cingulate cortex. We used multibarrel iontophoresis to identify the neurotransmitter used in this thalamic projection. Extracellular responses were recorded from 165 cingulate neurons in anesthetized rats after electrical stimulation of the medial dorsal thalamus and vicinity. Forty-four of these cells (27%) showed an excitatory response to thalamic stimulation. In a further 40 cells that showed no baseline excitation, iontophoresis of the GABAA antagonist bicuculline methiodide revealed excitatory responses. The GABAB antagonist CGP-35348 attenuated longer-latency inhibition in 5 of 10 cells. In 23 of 49 (47%) of the above cells, AMPA antagonist iontophoresis (either CNQX or DNQX) selectively decreased the excitatory response to thalamic stimulation. The NMDA antagonist 3[(R)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid had no such effect. These data suggest that the thalamic projection to anterior cingulate cortex is glutamatergic, acting principally via AMPA receptors, and that the response of cingulate neurons to thalamic stimulation is regulated by GABA acting at both GABAA and GABAB receptors.

Convergence of projections from the rat hippocampal formation, medial geniculate and basal forebrain onto single amygdaloid neurons: an in vivo extra- and intracellular electrophysiological study

We recorded extra- and intracellular responses from rat amygdaloid neurons in vivo after electrical stimulation of the hippocampal formation (dentate gyrus, hippocampal fields CA3 and CA4, entorhinal cortex, subicular complex); medial geniculate; and basal forebrain (diagonal band, ventral pallidum, olfactory tubercle, nucleus accumbens, bed nucleus of stria terminalis, lateral preoptic area, substantia innominata). Stimulation of hippocampal formation structures evoked IPSPs or EPSP-IPSP sequences in which the IPSP had a lower threshold than the EPSP. Recordings from candidate inhibitory neurons in the amygdala indicated that excitatory afferents from the hippocampal formation contact both amygdaloid inhibitory and principal neurons (feedforward inhibition), and that the inhibitory neurons have a lower threshold of activation. Medial geniculate stimulation also evoked EPSP-IPSP sequences. In marked contrast to these results, stimulation of basal forebrain structures evoked short latency IPSPs in amygdaloid neurons. This provides the first physiological evidence for direct inhibition of the amygdala by the basal forebrain. Basal forebrain stimulation also evoked EPSP-IPSP sequences in amygdaloid neurons. Individual amygdaloid neurons could show responses to stimulation of the hippocampal formation, basal forebrain, and medial geniculate, indicating that synaptic input from these areas converges onto single amygdaloid cells. The findings provide further information about the synaptic organization of afferents to the amygdala, and indicate that single amygdaloid neurons play a role in the synaptic integration of input from these diverse sources.

GABAergic synaptic transmission in projections from the basal forebrain and hippocampal formation to the amygdala: an in vivo iontophoretic study

We recorded extracellular responses from rat amygdaloid neurons in vivo after electrical stimulation of the basal forebrain and hippocampal formation. Iontophoretic application of the GABAA receptor antagonist, bicuculline, lead to the appearance of short latency evoked bursts after stimulation of either region. This occurred whether the baseline response was inhibitory or excitatory. Bicuculline only affected an early phase of inhibition, leaving a longer latency, longer duration phase unchanged or even increased. By contrast, the GABAB receptor antagonist, phaclofen, never produced such short latency evoked bursts. Both bicuculline and phaclofen increased the spontaneous rate of firing of amygdaloid neurons. The excitatory burst response to hippocampal formation stimulation of an amygdaloid candidate inhibitory neuron was blocked by CNQX (an antagonist of the AMPA subtype of glutamate receptor). Based on these and prior studies, it seems likely that the effects of hippocampal formation stimulation are mediated by feed-forward inhibition, in which GABAergic amygdaloid inhibitory neurons are excited by glutamatergic projections from the hippocampal formation. The effects of basal forebrain stimulation may be mediated by both feed-forward inhibition and direct, GABAergic inhibition.

Clinical features and haematological indices of bacterial infections in young infants

The clinical features and haematologic indices of 100 young infants aged 3 months and below, admitted with suspected bacterial infections, were analysed. Fever, lethargy, hepatomegaly, poor feeding and irritability were the commonest features for suspecting a bacterial infection in these infants. However, the features significantly associated with bacterial infections were respiratory distress and cyanosis. Of the haematologic indices commonly associated with bacterial infections, only C-reactive protein and erythrocyte sedimentation rate were significantly predictive compared to leukocyte counts, absolute neutrophil counts and nitro-blue tetrazolium tests. When used in combination, a raised C-reactive protein with erythrocyte sedimentation rate, a raised erythrocyte sedimentation rate with abnormal leukocyte counts and a raised C-reactive protein with abnormal leukocyte counts were significantly associated with bacterial infections.

Functional connections of the rat medial cortex and basal forebrain: an in vivo intracellular study

Projections between the medial cortex and basal forebrain in the rat were demonstrated by intracellular recordings and the anterograde tracer Phaseolus vulgaris leucoagglutinin. Direct projections between these areas were indicated by antidromic action potentials, short latency (less than 5 ms) orthodromic potentials, and labeled axon terminals in the basal forebrain subsequent to iontophoresis of Phaseolus vulgaris leucoagglutinin into posterior cingulate cortex. High proportions of antidromic action potentials were encountered in responsive cortical neurons (66%) and basal forebrain neurons (97%). Antidromic latencies recorded in the basal forebrain (less than 1.0 ms) revealed fast ascending projections; cortical neurons showed both fast and slow descending projections (latencies of 0.3-3.7 ms). Relatively few synaptic potentials (none in the diagonal band of Broca) and sparse labeling of axon terminals observed in the basal forebrain indicated that the ascending projections may be the more physiologically important or, at least, densest pathway. Polysynaptic feedforward pathways were suggested through long latency (greater than 20 ms) inhibitory and excitatory postsynaptic potentials, the former being the more common response. Candidate inhibitory neurons were identified in both cortex and basal forebrain. Possible monosynaptic (less than 5 ms) inhibitory postsynaptic and antidromic responses in these cells provided evidence that candidate inhibitory neurons participate in the reciprocal pathways.

Functional reciprocal connections of the rat entorhinal cortex and subicular complex with the medial frontal cortex: an in vivo intracellular study

We used in vivo intracellular recording techniques in the rat in order to determine the properties of projections from the medial frontal cortex to the entorhinal cortex and subicular complex. Three main results were obtained. (1) A high proportion (65%) of neurons within the medial frontal cortex were antidromically activated at short latency (0.4-1.9 ms) by electrical stimulation of the entorhinal cortex or subicular complex. This provided physiological evidence for fast direct projections from the medial frontal cortex to the entorhinal cortex and subicular complex. (2) Clear excitatory postsynaptic potentials (EPSPs) were evoked in 8% of the cells within the entorhinal cortex, subicular complex, or adjacent cortices after electrical stimulation of the medial frontal cortex. (3) The most salient synaptic response was inhibition, as shown by the presence of inhibitory postsynaptic potentials (IPSPs) in 50% of the cells sampled. Similar results were obtained for the reciprocal pathway: 56% of the sampled cells in the entorhinal cortex or subicular complex responded with antidromic spikes to stimulation of the medial cortex; 4% of medial frontal neurons responded to stimulation of the entorhinal cortex or subicular complex with clear EPSPs, and 48% with IPSPs. The latencies of most synaptic responses, 15-25 ms, were inconsistent with monosynaptic activation. This suggests that oligosynaptic relays amplified the signal within or en route to their targets, and/or that cells with more slowly propagating axons were also present but not sampled by the intracellular electrodes. Finally, responsive fast-spiking cells (candidate inhibitory neurons) were encountered within target structures. The results provide evidence that these distant cortical regions are functionally connected in a reciprocal manner, and that both principal and inhibitory neurons are excited by this projection system.

Chemotherapy for hepatoblastoma in children

Hepatoblastoma is an uncommon but highly malignant liver tumour found in childhood. It is associated with high mortality with overall survival of only 35%. Two cases of hepatoblastoma are described. Both had surgical excision of tumour with microscopic residual tumour at the resected margins. They were given adjuvant chemotherapy. Both patients are living well, disease-free and off treatment six years and two years since diagnosis.